Drive assembly incorporating stitch size adjustment device for automatic pattern-stitch sewing machine



May 12,1970

T. HESZ DRIVE ASSEMBLY INCORPORATING STITCH SIZE ADJUSTMENT DEVICE FOR AUTOMATIC PATTERNSTITCH SEWING MACHINE Filed Dec. 29, 1966 4 Sheets-Sheet 1 Fig.1

II-E.

Theodor Hesz Invenfor.

Attorney May 12, 1970 T. HESZ 3,511,19

DRIVE ASSEMBLY INCORPORATING STITCH SIZE ADJUSTMENT DEVICE FOR AUTOMATIC PATTERN-STITCH SEWING MACHINE Filed Dec. 29, 1966 4 Sheets-Sheet 2 Theodor Hesz Invenfor.

Attomey May 12, 1970 T. HESZ 3,

' DRIVE ASSEMBLY INCORPORATING STITCH SIZE ADJUSTMENT DEVICE FOR AUTOMATIC PATTERN-STITCH SEWING MACHINE Filed Dec. 29, 1966 4 Sheets-Sheet 5 Fig-3 Theodor Hesz In venfor.

May 12, 1970 T. HE sz 3,511,196

DRIVE ASSEMBLY INCORPORATING STITCH SIZE ADJUSTMENT DEVICE FOR AUTOMATIC PATTERN-STITCH SEWING MACHINE Filed Dec. 29, 1966 4 Sheets-Sheet 4.

Fig.5

Fig.6

Theodor Hesz In ven for.

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Attorney United States Patent 3,511,196 DRIVE ASSEMBLY INCORPORATING STITCH SIZE ADJUSTMENT DEVICE FOR AUTOMATIC PAT- TERN-STITCH SEWING MACHINE Theodor Hesz, Vienna, Austria, assignor to Arthur Schmid, Romanshorn, Switzerland, a corporation of Switzerland Filed Dec. 29, 1966, Ser. No. 605,701 Claims priority, application Switzerland, Dec. 30, 1965, 18,176/ 65 Int. Cl. D05b 11/00 US. Cl. 112-118 3 Claims ABSTRACT OF THE DISCLOSURE A drive assembly for a quilting "machine having a patterning cam or disk for controlling the feed rolls and wherein a cam plate is rotatably entrained with the main drive shaft but is axially shiftable therealong. Axial movement of the cam brings it into selective contact with at least one spring-biased pusher rod which controls a stepping device for the patterning disk to vary the stitch size.

The invention relates to a drive assembly with a stitchsize adjustment device to drive an automatic patternsewing or quilting machine with continous drive to the main drive shaft for the pattern device and its incorporated needles and shuttles and a stepped switching device integrally connected therewith for the staged drive of a pattern disc displacing the material guide back and forth and of the material feed rollers. As is well known, the majority of textile-processing machines date from the end of the nineteenth century and are very complicated devices. This may well be the reason why until recently no significant improvements were made in pattern-stitch sewing machines. It has been accepted as necessary that a new pattern disc be inserted for each new pattern and that the toothed wheels changed to vary the size of the stitches. The invention has as its object to create a modern drive assembly which is capable of being operated simply and can be housed in a closed housing. Pref erably this housing will be filled with oil, so that the components of the drive mechanism are lubricated at all times.

The drive assembly in accordance with the invention is distinguished by the fact that the assembly comprises at least one cam plate mounted on the main drive shaft so as to be torsionally rigid (rotatably entrained) therewith but axially capable of being displaced and capable of being brought intentionally by means of an axial displacement into the effective range of at least one spring-pressured push rod; the latter rotates on both the pattern disc and the material feed roller with one of the steps determining stitch size at a time and by way of a stepped switching device. As is well known, in the case of such pattern-stitch automatic machines, the lateral advancement of the material guide is always carried out in the rhythm of the sewing process in such wise that it takes place when the needles have withdrawn from the material and the presser foot has released the material. The advance of the material-feed rollers causes a movement of the material in the longitudinal direction of the web of material, while by contrast the guide advances the material at right-angles thereto. On adjustment of the size of stitch both the feed in the longitudinal direction and the lateral direction are simultaneously increased or reduced, as will be seen from the following description.

In the drawing an automatic pattern-stitch sewing machine with the new drive assembly and components thereof are shown by way of example and in simplified form:

FIG. 1 shows an automatic pattern-stitch sewing machine with its drive assembly viewed from above;

FIG. 2 shows components of a drive assembly in perspective;

FIGS. 3 and 4 show certain details of the same assembly viewed from the side or from above as the case may be;

FIG. 5 shows a variant with a multiple cam plate pack viewed from above, and

FIG. 6 shows the multiple cam plate pack of FIG. 5 magnified in side view.

FIG. 1 shows an automatic pattern-stitch sewing machine with the new drive assembly in simplified presentation in which for the sake of clarity the actual patternstitch sewing device including the row of needles that move up and down, the yarn feed etc. have been omitted. The automatic machine embodies a frame A on the righthand side of which a drive housing B with the new drive assembly is mounted, the latter being driven by a motor C. 0n the frame a material guide E is shiftable within trestle arms D (i.e. the arms of the frame carrying the drive assembly). The material guide is provided with a material-feed roller F and a roller G on to which the material web when finally pattern-stitched is rolled. It is additionally fitted with material feed rollers H and material feed rollers J. On the frame is located a needle bed K (shown for the sake of simplicity with only one row of needles N) and the main drive shaft L is also borne on it and drives the actual pattern-stitch sewing device, not shown. The shaft is driven directly by the drive assembly B by way of a rigid clutch Q. The rate of rotation in revolutions per minute of this main drive shaft determines the speed at which the automatic machine functions. By the use of a V-belt drive with variable gear ratios between the motor and the main drive shaft, the operating speed of the automatic machine can be adjusted. (In the drawing a non-variable V-belt drive is illustrated for the sake of simplicity.) On top of the drive housing B under a hinged cover R is located an easily interchangeable pattern disc (pattern-repeat wheel) U of a type in fact well known. Its shape determines the pattern M stitched by the automatic machine. In fact it carries out a directing influence on the back and forth movement of the material guide E, to which purpose the latter is displaced by one stitch increment at a time in the cadence of the pattern stitching by the drive assembly by way of a push rod V. By means of a handwheel W the size of the stitches can be regulated in stages. On adjustment a simultaneous alteration is made to the number of revolutions which the main drive shaft must make before the pattern disc has completed one full rotation and to the length of feed per stitch. A shaft X which protrudes beyond the drive housing and is coupled to one of the rollers I by means of a sliding splined shaft effects the advancement of the material web St stitch by stitch. In FIG. 1 the various movements are denoted by arrows. The full line directional arrow L on the main drive shaft indicates a continuous movement by this shaft, while the dotted arrows V and X are intended to denote a stitch by stitch motion.

FIGS. 2, 3 and 4 show the important components of a drive in simplified, perspective form. Here may be seen the continuously turning main drive shaft L, the drive shaft X effecting the feed of the material which drives one of the material advance rollers and the push-rod V which moves the material guide laterally.

This drive is described in detail hereunder and its method of operation explained. Motor C drives by way of a V-belt 200 a belt pulley 201 which is fitted integrally to the main drive shaft L. The latter turns continuously. Together with the shaft L there also turn the cam discs 202 and 203. By means of the spline 204 they are mounted torsionally rigid to the drive shaft L but can be displaced axially along it. Displacement is carried out by means of a sleeve 205 which can be pushed back and forth laterally by means of the fork 206, the toothed slide piece 207, the pinion 208 and the handwheel 209. These parts can be seen on a larger scale in FIGS. 3 and 4. Here the sleeve has been omitted and replaced by two forks 206 lying laterally adjacent to the cam discs. In the figure the cam disc 202 now works in conjunction with the spring-biased push rod 210, the pawl 213 of which engages in a ratchet wheel 214 with 60 teeth. This is mounted rigid on a shaft 215. A U-shaped bracket 216 which moves back and forth with the push rod 210 is mounted to pivot around the shaft and engage in the ratchet wheel. In the push rod a pin 217 is fitted which engages in the opening in the bracket 216 and at the same time holds a pressure spring 218. At the front the push rod 210 is forked at 219 and bears a roller 220 which runs on the cam disc 202. The roller turns about a shaft 221 which is itself borne in the pivoting plates 222. These plates are capable of being pivoted about a shaft 223 borne on the base 224 of the drive housing B. The roller 220 is pressed by means of the pressure spring 225 against the cam disc 202. The spring 225 is located in a spring guide sleeve 226 which is capable of being pivoted about a shaft 227 and the latter is held by means of a bearing 228 on the base of the housing. Inside the sleeve is fitted a removable shoulder stock 229 and the movement of the spring is capable of being adjusted accurately by means of a screw thread 230, a threaded sleeve 231 and an arrester nut 232. Sleeve 231 is pivoted at 231' to the plates 222. By means of the handwheel 209 the cam discs 202 and 203 can be brought into operation in turn 'by means of the cam-follower rollers at the ends of rods 210, 211, 212. These are distinguished from the push rods already described by the fact that they are in contact with ratchet wheels 214 with 80 teeth and 214" with 100 teeth. The shaft 215 is then turned by a different (small) angle according to the case. The shaft 215 is integral with a worm 250 which meshes with a worm wheel 251. The latter is rigidly connected to the vertical shaft 252 which bears on its upper end the easily exchangeable pattern disc U. On rotation of the shaft 252 the pattern disc moves the slide 254 once back and forth by means of the rollers 253 resting on it, in accordance with the pattern stitch desired. The vertical shaft 252 also has fixed to it a conical toothed wheel 255 which mates with the conical sprocket 256. This drives a shaft 257 to which a toothed wheel 258 is fitted, the latter being fixed to the shaft X and meshing with the toothed wheel 259. When for example the worm gear ratio is 1:10 and the reach distances of the cam discs 202, 203 are so selected that the ratchet wheels turn each time by one or two teeth, the following ratios can be attained:

Cam 202 on roller 220For l rotation of shaft L produces rotation of shaft 215, i.e. 600 stitches on the pattern repeat wheel (pattern disk) U. Similarly:

Cam 203 on roller 220-300 stitches on the repeat wheel Cam 202 on roller 220'800 stitches on the repeat wheel Cam 203 on roller 220'400 stitches on the repeat wheel Cam 202 on roller 220"1000 stitches on the repeat wheel Cam 203 on roller 220 500 stitches on the repeat wheel 4 The ratio for the shaft X Will be so selected that the material guide rollers will advance the material to be pattern stitched at the proper rate below the needles.

In FIGS. 5 and 6 a variant of the drive is illustrated. Instead of a number of ratchet wheels there is only one ratchet wheel here, but on the other hand a considerable number of cam discs combined into a pack are used. The side view of this mechanism corresponds to FIG. 3. Ac cordingly, the same reference figures have been used for similar components. The multiple cam plate pack comprises six cam discs with different reach, by which means for example rotation of the ratchet wheel 214 by from 1 to 6 teeth can be achieved. Using a ratchet wheel with 96 teeth and a worm gear ratio of 1:10 the following advance steps (or numbers of stitches) can be attained.

Advance of l toothFor 1 revolution of the shaft L the shaft 215 makes A revolution corresponding to a stitch figure of 960 on the pattern repeat wheel.

Advance of 2 teeth480 on the pattern repeat wheel Advance of 3 teeth-620 on the pattern repeat wheel Advance of 4 teeth240 on the pattern repeat Wheel Advance of 5 teeth192 on the pattern repeat wheel Advance of 6 teeth on the pattern repeat wheel FIG. 6 shows such a multiple carn plate pack 300 from the side view. It is of course possible without more ado to replace the ratchet wheels by freewheel clutches with clamping elements. But these usually display a degree of slip which in the layout selected becomes cumulative and may lead to considerable errors.

Preferably the drive housing B shown in FIG. 1 will be filled with oil so that all com onents are kept constantly lubricated. At points where shafts pierce the housing walls below oil level, the transition openings are sealed oilproof. The vertical shaft 252 which bears the pattern disc U at its upper end, protrudes beyond the oil level and therefore requires no special obturation. The pattern disc Ubeneath the cover R is situated in the open and can therefore be exchanged easily.

What is claimed is:

1. An automatic pattern-sewing machine comprising, in combination:

a main drive shaft;

a vertically shiftable needle array operatively connected with said drive shaft for pattern stitching a fabric displaced past said array;

fabric-transport means operatively connected with said main drive shaft for displacing said fabric past said array, said fabric-transport means including:

a fabric support reciprocable substantially in the plane of said fabric, and

transport-roller means carried by said support and engaging said fabric for drawing said fabric along said support;

an exchangeable pattern disk rotatable for reciprocating said support; and

a drive assembly operatively connecting said main drive shaft with said pattern disk and said transport-roller means, said drive assembly including:

cam means having an endless cam surface rotatably entrained by said main drive shaft and axially shiftable therealong,

a plurality of cam-follower rods axially spaced along said main drive shaft and shiftable transversely thereto while having respective camroller portions selectively engageable by said cam surface for displacing said rods.

means biasing said rods in the direction of surface,

a common shaft operatively connected to transport-rolling means and said pattern for jointly rotating same in synchronism,

a plurality of ratchet Wheels fixed to said common shaft in axially spaced relationship therealong and with different members of teeth, each of said said disk said rods being formed with a pawl at its extremity remote from said surface and co-operating with a respective one of said wheels for stepping same to incrementally rotate said common shaft to a degree determined by the particular rod displaced by the cam surface and the number of teeth of the corresponding ratchet wheel, and

control means for shifting said cam means along said main drive shaft to select the rod engageable by said surface.

2. The combination defined in claim 1 wherein said means biasing said rods in the direction of said surface includes a respective spring bearing upon each of said rods and urging same toward said main shaft and into engagement with said cam means, said cam means comprising a plurality of axially offset endless cam surfaces, each selectively engageable with each of said rods.

3. The combination defined in claim 2 wherein said system is contianed in a sealed housing, said control means comprising a rackand-pinion arrangement with a pinion shaft extending from said housing, said housing being filled with oil.

References Cited UNITED STATES PATENTS Shotsky 1121l7 X Baehr 112-16() Manning et al. 11279 Schlegel 112118 Barnes 11279 Boettcher 112-117 Krogh et al. 7454 X Grunke 74568 X Eguchi 112158 Kuhn 112-118 Story 112--118 M. STEIN, Primary Examiner 20 GEO. V. LARKIN, Assistant Examiner 

